Merge

hotspot/src/share/vm/gc/parallel/mutableNUMASpace.cpp

@@ -30,11 +30,21 @@
 #include "runtime/atomic.hpp"
 #include "runtime/thread.inline.hpp"
 
-MutableNUMASpace::MutableNUMASpace(size_t alignment) : MutableSpace(alignment) {
+MutableNUMASpace::MutableNUMASpace(size_t alignment) : MutableSpace(alignment), _must_use_large_pages(false) {
   _lgrp_spaces = new (ResourceObj::C_HEAP, mtGC) GrowableArray<LGRPSpace*>(0, true);
   _page_size = os::vm_page_size();
   _adaptation_cycles = 0;
   _samples_count = 0;
+
+#ifdef LINUX
+  // Changing the page size can lead to freeing of memory. When using large pages
+  // and the memory has been both reserved and committed, Linux does not support
+  // freeing parts of it.
+    if (UseLargePages && !os::can_commit_large_page_memory()) {
+      _must_use_large_pages = true;
+    }
+#endif // LINUX
+
   update_layout(true);
 }
 
@@ -578,6 +588,10 @@ void MutableNUMASpace::initialize(MemRegion mr,
   // Try small pages if the chunk size is too small
   if (base_space_size_pages / lgrp_spaces()->length() == 0
       && page_size() > (size_t)os::vm_page_size()) {
+    // Changing the page size below can lead to freeing of memory. So we fail initialization.
+    if (_must_use_large_pages) {
+      vm_exit_during_initialization("Failed initializing NUMA with large pages. Too small heap size");
+    }
     set_page_size(os::vm_page_size());
     rounded_bottom = (HeapWord*)round_to((intptr_t) bottom(), page_size());
     rounded_end = (HeapWord*)round_down((intptr_t) end(), page_size());

hotspot/src/share/vm/gc/parallel/mutableNUMASpace.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -145,6 +145,8 @@ class MutableNUMASpace : public MutableSpace {
   size_t _page_size;
   unsigned _adaptation_cycles, _samples_count;
 
+  bool _must_use_large_pages;
+
   void set_page_size(size_t psz)                     { _page_size = psz;          }
   size_t page_size() const                           { return _page_size;         }
 

hotspot/test/gc/arguments/TestSmallInitialHeapWithLargePageAndNUMA.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test TestSmallInitialHeapWithLargePageAndNUMA
+ * @bug 8023905
+ * @requires os.family == "linux"
+ * @requires vm.gc.Parallel
+ * @summary Check large pages and NUMA are working together via the output message.
+ * @library /testlibrary /test/lib /test/lib/share/classes
+ * @modules java.base/jdk.internal.misc
+ * @modules java.management/sun.management
+ * @build TestSmallInitialHeapWithLargePageAndNUMA
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -XX:+UseHugeTLBFS -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI TestSmallInitialHeapWithLargePageAndNUMA
+*/
+
+import jdk.test.lib.ProcessTools;
+import jdk.test.lib.OutputAnalyzer;
+import sun.hotspot.WhiteBox;
+
+public class TestSmallInitialHeapWithLargePageAndNUMA {
+
+  private static final String MSG_EXIT_TOO_SMALL_HEAP = "Failed initializing NUMA with large pages. Too small heap size";
+  private static final String MSG_GC_TRIGGERED_BEFORE_INIT = "GC triggered before VM initialization completed.";
+
+  public static void main(String[] args) throws Exception {
+
+    WhiteBox wb = WhiteBox.getWhiteBox();
+    long heapAlignment = wb.getHeapAlignment();
+
+    // When using large pages, Linux does not support freeing parts of reserved and committed memory.
+    // And current Linux implementation uses page size as a condition to actually freeing memory.
+    // If we allocate pages less than NUMA node, NUMA will try to use default page size and
+    // this will free the memory which Linux does not support.
+    // Assume the minimum NUMA node as 2.
+    long initHeap = heapAlignment;
+    long maxHeap = heapAlignment * 2;
+
+    String[] vmArgs = {"-XX:+UseParallelGC",
+                       "-Xms" + String.valueOf(initHeap),
+                       "-Xmx" + String.valueOf(maxHeap),
+                       "-XX:+UseNUMA",
+                       "-XX:+UseHugeTLBFS",
+                       "-XX:+PrintFlagsFinal",
+                       "-version"};
+
+    ProcessBuilder pb_enabled = ProcessTools.createJavaProcessBuilder(vmArgs);
+    OutputAnalyzer analyzer = new OutputAnalyzer(pb_enabled.start());
+
+    if (largePageOrNumaEnabled(analyzer)) {
+      // We reach here, if both NUMA and HugeTLB are supported.
+      // However final flags will not be printed as NUMA initialization will be failed.
+      checkAnalyzerValues(analyzer, 1, MSG_EXIT_TOO_SMALL_HEAP);
+    }
+  }
+
+  // If both NUMA and large pages are enabled, VM will exit during NUMA initialization
+  // under the small heap configuration. So final flags will not be printed.
+  private static boolean largePageOrNumaEnabled(OutputAnalyzer analyzer) {
+    String output = analyzer.getOutput();
+
+    return !output.contains("[Global flags]");
+  }
+
+  // We need to test with small heap but fastdebug binary fails to initialize because of the small heap.
+  // So skip that case.
+  private static void checkAnalyzerValues(OutputAnalyzer analyzer, int expectedExitValue, String expectedMessage) {
+    String output = analyzer.getOutput();
+
+    // If the VM exits because of the small heap, skip checking the exit value.
+    if (!output.contains(MSG_GC_TRIGGERED_BEFORE_INIT)) {
+      analyzer.shouldHaveExitValue(expectedExitValue);
+    }
+    if (expectedMessage != null) {
+      analyzer.shouldContain(expectedMessage);
+    }
+  }
+}